It's hard to know what they mean by "next generation tram". Perhaps they
mean that Chinese trackless bus! The E is the current design most-adopted
for systems requiring trams with swivelling bogies and is available from
most of the major manufacturers. The Skoda 15T would be a better tram (not
least for having a full complement of six doors and a wider aisle), but
otherwise I can't see any design issue with the E that's been superceded by
newer designs. There aren't any, nor is there any sign of further
signficant development in basic low-floor tram design - where there is now
a stable range of design options - anywhere on the horizon. Maybe it's no
more than political waffle.

Tony P